1. Technical Field
The present invention relates generally to heat exchangers, and more particularly relates to headers for heat exchangers.
2. Background Information
Typically, automotive vehicles are provided with an engine cooling system with a heat exchanger, such as a radiator. When the engine is running, heat is transferred from the engine to a coolant that flows through the engine, thereby cooling the engine. The coolant then flows from the engine to the heat exchanger through a series of conduits. At the heat exchanger, heat is transferred from the coolant to cooler air that flows over the outside of the heat exchanger. This process repeats itself in a continuous cycle.
A typical heat exchanger includes a series of tubes supported by two headers. One type of conventional header is a flat header. When these flat headers are joined to a respective tube, for example, by brazing, the joint between the header and the tube lies in a flat plane. These types of header/tube combinations are prone to failure because of the stress concentrations that occur along the header/tube joint. These stresses are typically attributable to the thermal loading (i.e., stresses induced by the rise and fall of the temperature of the heat exchanger components) on the header and tubes during the operation of the engine.
From the above, it is seen that there exists a need for an improved heat exchanger header that experiences less thermal loading.